Stress is a significant factor that can precipitate, exacerbate, and maintain psychopathology. Various neurotransmitter systems and intracellular transduction pathways have been implicated in mediating the stress response and linking it to psychopathology. The corticotropin-releasing factor (CRF) system is among the most important systems that have been identified. Over-activity of the CRF system is implicated in depression, anxiety and other stress-related disorders, and novel treatments aimed at reducing activity of the CRF system may be very effective for these disorders. Furthermore, abundant preclinical evidence supports the likelihood that treatments targeting this system offer a promising approach for treating certain neuropsychiatric, as well as other stress-related illnesses. At this time, few new therapeutic agents for the treatment of depression, anxiety and other stress-related disorders are in the pipeline. Promoter Neurosciences (PNS) has developed a high throughput screen for the detection of compounds that alter expression of the CRF2(a) receptor through its promoter. Our previous studies have validated the assay and have demonstrated the ability to reliably identify compounds that alter expression from the CRF2(a) promoter in a dose-dependent manner. In this proposal, we plan to perform a series of experiments to develop lead compounds that decrease expression from the CRF2(a) promoter. We have screened a library of 59,330 small molecules and have discovered numerous novel compounds that alter expression from the CRF2(a) promoter. First, we will assess the specificity of these hits, selecting those that do not affect expression from several other promoters. Secondly, by collaborating with medicinal chemists we will perform "hit to lead optimization." Thirdly, we will construct a cell line that expresses the CRF2(a) protein under control of the CRF2(a) promoter fragment used in the screening assay. This cell line will be used to demonstrate that the changes in transcription elicited by the identified compounds translate into changes in CRF2(a) protein levels. Furthermore, the ability of the compounds to alter function will be determined by examining changes in CRF2(a) receptor-induced increases in cAMP levels. Finally, we will administer the lead compounds to rats to assess changes in CRF2(a) receptor binding and the effects of the lead compounds on behavior using established models of anxiety. [unreadable] [unreadable] [unreadable] [unreadable]